"Grandma" to my little guy announced last night that her bio daughter is pg. And I feel bad about it, but I'm... jealous? upset? I'm not real sure what I'm feeling, but it's not nice. Like she's only doing it because I did? dunno. Maybe it's just hormones.

Part of it I'm sure is knowing that her marriage hasn't been the most stable, or maybe it's that with the announcement was the info that she's having an u/s this week, when she can't be more than 8 wks... which implies that she's just doing what the doctor tells her (and I think we all know how I feel about that).

Just needed to vent a bit, since the person I usually tell these things to, my BFF is her sister.

I think it's probably one of those inexplicable Mommy feelings. I know I felt a little like that when each of my SILs had kids. Like they're somehow taking attention/love away from my kids, yk? So stupid - but I felt it none the less.

Don't worry, you've got lots of time to let it grow on you. And hopefully you'll be an AUNT soon!

i know exactly how you feel!
in my family, both between marriage and my sisters- i've had two women have babies after i had my first, for the attention. i'm a pretty shy person, and am so not into being lavished with attention from people who aren't extremely close to me. my husband's sister has always competed with him, and after we had our first, she had to get preg again. she would get so jealous over people loving on our baby- always forcing her youngest into the mix. dh and i found it comical. then my older sis- a total nut, drug addicted, bi-polar, emotional mess who is always victimizing herself, and forever competing with me, got pg. now, 1.5 years after her dd was born, the attention is over, and my sis can't take it. she hates her dd, and tho she's a sahm, dd is in daycare for 10 hours a day! no one in our family is happy about this. everyone who knows her hoped when she had a baby it would change her, give her a reason to feel loved and happy. everyone hoped it wouldn't make her crazier and angrier. and through all this, she talks about starting to ttc again in the next year (b/c my 2nd lo was just born!)! i think its just the dumbest thing in the world to have kids in competition!

Yeah, I've been there. It sucks and I'm sorry for you.
When I was 4 months pg with DS, my SIL announced she was pregnant too. I felt big time like she was stealing my thunder. It didn't help matters when she announced they were going to name the baby "Olivia" if it was a girl, after we had already chosen the name "Oliver" for a boy. That was pretty lame. It's kind of funny in hindsight, but at the time I was LIVID. And then she had a girl, the first grandaughter, and I know gender isn't something you can plan, but their family really went gaga over the new baby and she's kind of the favorite now, which hurts. But what can you do, right? I've just kind of tried to enjoy my own babies for the blessings they are, and not think about all that family politics stuff too much.
But congratulations on a new cousin for your LO! At least they'll be close in age and can play together!